I've thought about the R61, although I find myself quite attached to my T61. I expect to keep my T61 even if the situation allowed for my being able to buy another current T or W model. However, it's not just sentiment has me wondering about a BD option. It's also the frustration at how close the T61 came to having this option. I mean, it's not as if I were a
T42 owner asking for this. This option was a reasonable expectation...at least for a time.
As for frequency of use, I could see myself burning 30-40GB to disk every other month at most. But even if less often, the appeal of burning tens of gigabytes to a disc that need not be powered, take a USB slot, nor handled with kid gloves (ok, don't
scratch it) is great. In one zippered padded case, I could carry several terabytes of backups. Such a case would also survive a drop better than a 1.5TB external hard drive (biggest, ATM). Also, don't forget the price for said external drive, the
same external drive sold a year previously, has almost doubled in price due to the recent HD crisis.
On the other hand, BD media isn't cheap either, but it's getting cheaper and I can buy it in affordable quantities as time goes on versus saving up for an external HDD. You said you had a media issue three years ago, and there may still be some, but that
was three years ago. I remember from my days at CDF, that changes in write methods and firmware releases happened in months and
weeks. I expect the situation to have probably improved. Insofar as using one externally, you said it yourself, it can be slow. I haven't ruled out attempting to just get an external, or a bare drive and an enclosure, but when burning such a disc over time, I worry about an accidental cable pull. There's less risk with a DVD due to shorter burn times, but I still prefer to burn DVD's internally for the same reason. That's one of the reasons I had considered the Advanced Dock as seriously as I had.
Now, despite my concerns over external hard drives, I actually do have a few. Yet, one other drawback aside from their cost, power consumption, and fragility, is (ironically) that they are rewritable media. Archiving, especially backups, are things I'd like to do with media that is designed for this purpose. While I would want the option to burn BD-RW media, and likely would, long-term backups would be something I would prefer to save to media destined for it. Once saved, write-once media allows no accidental erases or deletions. I used to buy DVD-DL discs in the past for this purpose, although I find 8GB rather small now.
Lastly....well, wouldn't it be great to mod such a thing together? I only wish I had a stack of burners I could toy with to see if it could be done. Of course, that's another dream as well.
